A novel approach for the oxidative catalysis employing polyoxometalate-laccase system: application to the oxygen bleaching of kraft pulp

A novel approach for the catalytic oxygen bleaching of kraft pulp using the heteropolyanion [SiW11MnIII(H2O)O-39](5-) (SiW11 Mn-III) and laccase of Trametes versicolor is proposed. The oxidation of the residual lignin in pulp with the heteropolyanion was followed by the catalyst re-oxidation by laccase in a separate stage. The alterative treatment in a multi-stage process with SiW11MnIII at 110 degreesC and with laccase at 45 degreesC allowed a sustainable eucalypt kraft pulp delignification with removal of about 50% of the residual lignin with minimal polysaccharides damage. Heteropolyanion maintained stable after redox turnovers during the treatments. (C) 2004 Elsevier B.V. All rights reserved.